In December 2014 a photographic survey of Black browed Thalassarche melanophris and Grey-headed T. chrysostoma Albatrosses was undertaken around the South Atlantic island of South Georgia (Islas Georgias del Sur)*.  Because the breeding colonies are mainly located on steep coastal headlands and sea cliffs it was not possible to gain access from the land so a vessel was used to support a two-person team to photograph the colonies from the water.

A report on the survey is precised here:

“At the end of the 14-day trip, more than 1,000 photos had been taken including close up shots and perspectives at 12 locations.  Using the photographs as a guide, images of discrete colonies or groups of birds were ‘stitched’ together.  Some colonies lacked clearly defined boundaries due to the complexities of terrain and so landscape features such as ridges and spurs were used to define counting areas.  The location of each individual albatross was highlighted on the computer screen by superimposing a coloured dot on each bird, and these dots were then counted.

After the total number of birds in each colony was counted, the numbers of breeding pairs were corrected for diurnal variation and for nest failure between the date of laying and the date each colony was censused [sic].  More than 15,000 black-browed and 16,000 grey-headed albatross were recorded but unfortunately this still signifies a considerable decline since the previous survey in 2004.  For the black-browed albatross this represents around a 20% decline in the population but for grey-headed it is more than a 40% decline.”

Black-browed Albatross, photograph by Oli Yates

Click here to access the original report in full.

Relevant Literature:

Poncet, S., Robertson, G. Phillips, R.A., Lawton, K., Phalan, B., Trathan, P.N. & Croxall, J.P. 2006.  Status and distribution of wandering, black-browed and grey-headed albatrosses breeding at South Georgia.  Polar Biology 29: 772-781.

John Cooper, ACAP Information Officer, 09 July 2015

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

Graham Parker (Parker Conservation, Dunedin, New Zealand) and colleagues have submitted a draft report to last month’s meeting of the Conservation Services Programme (CSP) of New Zealand’s Department of Conservation on a survey of ACAP-listed Grey Petrels Procellaria cinerea on Campbell Island.

The report’s abstract follows:

“Populations of grey petrels have declined due to both incidental capture in commercial fisheries and predation by introduced mammals at breeding sites.  In the New Zealand region grey petrels breed only on Campbell and Antipodes islands.  Rats were successfully eradicated from Campbell Island in 2001.  To investigate if the grey petrel population had expanded since the rat eradication, we defined the population’s spatial extent and produced the first quantitative population estimate on Campbell Island and surrounding islets.  We found no clear increase in the number of grey petrels breeding on Campbell Island relative to a historic, non-quantitative population estimate.  However, two of the four colonies we found are either recently established or previously went unidentified.  We estimated 90 pairs of breeding grey petrels from the four colonies located.  This underestimates the breeding population since work was conducted during the mid chick-rearing stage.  There may be grey petrels breeding on the off-shore islands that we could not survey, but if so, the number there would not significantly increase the island-wide population estimate.  The Campbell Island grey petrel breeding population remains small.  Our study provides a baseline for future population estimates of grey petrels on Campbell Island.”

A Grey Petrel in its burrow, photograph by Peter Ryan 

Click here to view a presentation on the above report.

With thanks to Barry Baker.

Reference:

Parker, G.C., Rexer-Huber, K. & Thompson, D. 2015.  Are Grey Petrels Returning to Campbell Island? Survey and Census 14 years after Rodent Eradication.  Report to the Department of Conservation.  Dunedin: Parker Conservation.  18 pp.

John Cooper, ACAP Information Officer, 08 July 2015

Andrew Reynolds (Rothamsted Research, Harpenden, UK) and colleagues have published in the Proceedings of the Royal Society B on the ability of the three species of Calonectris shearwaters to navigate at sea using their sense of smell.

The paper’s abstract follows:

“Homing studies have provided tantalizing evidence that the remarkable ability of shearwaters (Procellariiformes) to pinpoint their breeding colony after crossing vast expanses of featureless open ocean can be attributed to their assembling cognitive maps of wind-borne odours but crucially, it has not been tested whether olfactory cues are actually used as a system for navigation.  Obtaining statistically important samples of wild birds for use in experimental approaches is, however, impossible because of invasive sensory manipulation.  Using an innovative non-invasive approach, we provide strong evidence that shearwaters rely on olfactory cues for oceanic navigation.  We tested for compliance with olfactory-cued navigation in the flight patterns of 210 shearwaters of three species (Cory's shearwaters, Calonectris borealis, North Atlantic Ocean, Scopoli's shearwaters, C. diomedea Mediterranean Sea, and Cape Verde shearwaters, C. edwardsii, Central Atlantic Ocean) tagged with high-resolution GPS loggers during both incubation and chick rearing.  We found that most (69%) birds displayed exponentially truncated scale-free (Lévy-flight like) displacements, which we show are consistent with olfactory-cued navigation in the presence of atmospheric turbulence.  Our analysis provides the strongest evidence yet for cognitive odour map navigation in wild birds.  Thus, we may reconcile two highly disputed questions in movement ecology, by mechanistically connecting Lévy displacements and olfactory navigation. Our approach can be applied to any species which can be tracked at sufficient spatial resolution, using a GPS logger.”

Read more about this publication here.

Scopoli's Shearwater at sea, photograph by Pep Arcos

Reference:

Reynolds, A.M., Cecere, J.G., Paiva, V.H., Ramos, J.A., Focardi, S. 2015.  Pelagic seabird flight patterns are consistent with a reliance on olfactory maps for oceanic navigation.  Proceedings of the Royal Society B  DOI:10.1098/rspb.2015.0468.

John Cooper, ACAP Information Officer, 07 July 2015

Ben Dilley (Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa) and colleagues have published in the journal Antarctic Science on the deleterious effects of introduced House Mice Mus musculus on the breeding success of seven species of burrowing seabirds on Gough Island, including the ACAP-listed Grey Petrel Procellaria cinerea.

The paper’s abstract follows:

“Since 2004 there has been mounting evidence of the severe impact of introduced house mice (Mus musculus L.) killing chicks of burrow-nesting petrels at Gough Island.  We monitored seven species of burrow-nesting petrels in 2014 using a combination of infra-red video cameras augmented by burrowscope nest inspections.  All seven camera-monitored Atlantic petrel (Pterodroma incerta Schlegel) chicks were killed by mice within hours of hatching (average 7.2±4.0 hours) with an 87% chick failure rate (n=83 hatchlings).  Several grey petrel (Procellaria cinerea Gmelin) chicks were found with mouse wounds and 60% of chicks failed (n=35 hatchlings).  Video surveillance revealed one (of seven nests filmed) fatal attack on a great shearwater (Puffinus gravis O’Reilly) chick and two (of nine) on soft-plumaged petrel (Pterodroma mollis Gould) chicks.  Mice killed the chicks of the recently discovered summer-breeding MacGillivray’s prion (Pachyptila macgillivrayi Mathews), with a chick mortality rate of 82% in 2013/14 and 100% in 2014/15.  The closely-related broad-billed prion (P. vittata Forster) breeds in late winter and also had a chick mortality rate of 100% in 2014.  The results provide further evidence of the dire situation for seabirds nesting on Gough Island and the urgent need for mouse eradication.”

Grey Petrel, photograph by Peter Ryan

A one-minute video of an Atlantic Petrel chick being attacked by a mouse accompanies the publication.

With thanks to Alex Bond.

Reference:

Dilley, B.J., Davies, D., Bond, A.L. & Ryan, P.G. 2015.  Effects of mouse predation on burrowing petrel chicks at Gough Island.  Antarctic Science  DOI:http://dx.doi.org/10.1017/S0954102015000279.

John Cooper, ACAP Information Officer, 6 July 2015